London has been battered by 50mph winds that have felled trees and caused travel chaos. Powerful gusts swept across the capital as the Met Office issued a yellow "be aware" weather alert for most of the country.

International movers and shakers visiting London for the Olympics gathered at Clarence House to hear that Britain is "open for business".

The Prince of Wales hosted the reception, attended by Prime Minister David Cameron, Deputy Prime Minister Nick Clegg, Chancellor of the Exchequer George Osborne and the Duke of York following a global investment conference at nearby Lancaster House.

Among the guests at the event were Christine Lagarde, managing director of the International Monetary Fund, and the secretary general of the OECD, Angel Gurria.

The Prince of Wales chatted and laughed with Ms Lagarde, Mr Gurria and other guests as Britain's top politicians and business leaders schmoozed their international counterparts.

Earlier at the conference, the head of the European Central Bank, Mario Draghi, delivered an impassioned pledge to do "whatever it takes" to keep the euro together, which saw world markets rally higher. At the reception, politicians and business leaders delivered a similar message regarding the British economy and foreign investment.

Danny Alexander, Chief Secretary to the Treasury, said: "This is a hugely important part of getting the best for Britain from the fantastic opportunity to have the Olympic Games here. We have 200 delegates here today, some of the leading names in the world in economics and business, and it is the first of a series of events running over the time that the Olympics is going on and we are going to have 4,000 delegates from a whole range of business sectors.

"It is an opportunity to demonstrate that Britain is open for business, that this Government and this country is welcoming of overseas investment, is welcoming of businesses who are seeking to grow in the UK. A big part of what we can gain from the Olympics is the investment that comes from these conferences."

The soundtrack to the reception was provided by the Welsh Guards band, which played Chariots of Fire and the national anthem among others before saluting the Prince of Wales.

Sir Martin Sorrell, the chief executive of advertising and public relations firm WPP and an economic adviser to the Prime Minister, praised the country's political elite for "getting their business cards out".

Asked what Britain had to offer international investors as it goes through the worst double-dip recession for 50 years, he said: "Britain is a mature economy, it has first class education facilities, first class technology industries, first class creative industries. Infrastructure is very strong, there are improvements that can be made, we would all like to see better airports, but our geographical and time zone location is outstanding, we are in between east and west. All those things add up to a first-class opportunity for us."